USN-510-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-510-1

31st August, 2007

linux-source-2.6.20 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 7.04

Software description

  • linux-source-2.6.20


A flaw was discovered in the PPP over Ethernet implementation. Local
attackers could manipulate ioctls and cause kernel memory consumption
leading to a denial of service. (CVE-2007-2525)

An integer underflow was discovered in the cpuset filesystem. If mounted,
local attackers could obtain kernel memory using large file offsets while
reading the tasks file. This could disclose sensitive data. (CVE-2007-2875)

Vilmos Nebehaj discovered that the SCTP netfilter code did not correctly
validate certain states. A remote attacker could send a specially crafted
packet causing a denial of service. (CVE-2007-2876)

Luca Tettamanti discovered a flaw in the VFAT compat ioctls on 64-bit
systems. A local attacker could corrupt a kernel_dirent struct and cause
a denial of service. (CVE-2007-2878)

A flaw in the sysfs_readdir function allowed a local user to cause a
denial of service by dereferencing a NULL pointer. (CVE-2007-3104)

A buffer overflow was discovered in the random number generator. In
environments with granular assignment of root privileges, a local attacker
could gain additional privileges. (CVE-2007-3105)

A flaw was discovered in the usblcd driver. A local attacker could cause
large amounts of kernel memory consumption, leading to a denial of service.

Zhongling Wen discovered that the h323 conntrack handler did not correctly
handle certain bitfields. A remote attacker could send a specially crafted
packet and cause a denial of service. (CVE-2007-3642)

A flaw was discovered in the CIFS mount security checking. Remote attackers
could spoof CIFS network traffic, which could lead a client to trust the
connection. (CVE-2007-3843)

It was discovered that certain setuid-root processes did not correctly
reset process death signal handlers. A local user could manipulate this
to send signals to processes they would not normally have access to.

The Direct Rendering Manager for the i915 driver could be made to write
to arbitrary memory locations. An attacker with access to a running X11
session could send a specially crafted buffer and gain root privileges.

It was discovered that the aacraid SCSI driver did not correctly check
permissions on certain ioctls. A local attacker could cause a denial
of service or gain privileges. (CVE-2007-4308)

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 7.04:
linux-image-2.6.20-16-386 2.6.20-16.31
linux-image-2.6.20-16-powerpc 2.6.20-16.31
linux-image-2.6.20-16-server 2.6.20-16.31
linux-image-2.6.20-16-mckinley 2.6.20-16.31
linux-image-2.6.20-16-sparc64-smp 2.6.20-16.31
linux-image-2.6.20-16-powerpc64-smp 2.6.20-16.31
linux-image-2.6.20-16-hppa32 2.6.20-16.31
linux-image-2.6.20-16-itanium 2.6.20-16.31
linux-image-2.6.20-16-server-bigiron 2.6.20-16.31
linux-image-2.6.20-16-generic 2.6.20-16.31
linux-image-2.6.20-16-sparc64 2.6.20-16.31
linux-image-2.6.20-16-hppa64 2.6.20-16.31
linux-image-2.6.20-16-lowlatency 2.6.20-16.31
linux-image-2.6.20-16-powerpc-smp 2.6.20-16.31

To update your system, please follow these instructions:

After a standard system upgrade you need to reboot your computer to
effect the necessary changes.


CVE-2007-2525, CVE-2007-2875, CVE-2007-2876, CVE-2007-2878, CVE-2007-3104, CVE-2007-3105, CVE-2007-3513, CVE-2007-3642, CVE-2007-3843, CVE-2007-3848, CVE-2007-3851, CVE-2007-4308